TED Radio Hour - Why We're Living Longer

Episode Date: March 10, 2023

Original broadcast date: March 22, 2022. In the last century, human life expectancy has doubled. This hour, we talk with writer Steven Johnson on the many breakthroughs that made this possible — and where we go from here.See pcm.adswizz.com for information about our collection and use of personal data for sponsorship and to manage your podcast sponsorship preferences.NPR Privacy Policy

This is the TED Radio Hour. Each week, groundbreaking TED Talks. Our job now is to dream big. Delivered at TED conferences. To bring about the future we want to see. Around the world. To understand who we are. From those talks, we bring you speakers and ideas that will surprise you.

You just don't know what you're going to find. Challenge you. We truly have to ask ourselves, like, why is it noteworthy? And even change you. I literally feel like I'm a different person. Yes. Do you feel that way? Ideas worth spreading.

From TED and NPR. I'm Manoosh Zamoroti. And I want to start the show today with kind of an unusual question. If a newspaper only came out once a century, what would the banner headline be? What is the most important story on that scale? This is author Stephen Johnson. He's written more than a dozen books about science and innovation.

And when he asked me this question, my mind immediately went to the obvious answers. Which will live in infamy. The dawn of wars and the end of them. The surrendered terms of the United Nations. This, ladies and gentlemen, is the end of the Second World War. Or maybe the biggest story was the space race, how we put astronauts on the moon just 66 years after the right. Wright brothers first flew.

On this July 20th, 19169. That's one small step for man. Or if not that, then maybe the birth of computers and smartphones and having all of the information in the universe at our fingertips. What is Internet anyway? What do you write to it? Like mail? Internet is that massive computer network.

The one that's becoming really big now. But Stephen Johnson says all those guesses are wrong. To me, I really come down to the idea that it is the story of life expectancy. That basically, 100 years ago, as best as we know, average life expectancy around the world, global life expectancy, was somewhere around 35. And that's basically where it had been for almost all of human history. Now there's a huge swath of the world where life expectancy is above 70. There are many places now where life expectancy is above 80, which is extraordinary. And there's no country in the world.

where life expectancy is below 45 anymore. In fact, there are very few where life expectancy is below 60. So in other words, we have doubled the human lifespan in 100 years. Why don't we think of that as headline-worthy? So this is a great question. I'm so glad you asked it because what your mind naturally went to was an event, right? We landed on the moon. This thing happened. And there is something intrinsically satisfying about that kind of headline because it's tied to a really tangible story. You know, there's heroic astronauts and they go to the moon and they do this thing no human has ever done before and it's an amazing breakthrough. And, you know, it is an amazing breakthrough. I don't want to take anything away from the moon landing. But if you think about what

really matters in people's lives and day-to-day how your life is transformed to me adding a whole extra life, basically, adding this extra 35 years, that's a bigger deal than the fact that somebody walked on this big satellite circling our planet. I mean, it seems to me like that's a bigger thing. But the problem is it doesn't condense down to that clear, intelligible narrative the way the moon landing does. It's made up of slow, incremental progress, everything getting just a little bit better year after year and a thousand different interventions. from a number of different fields kind of aggregating up into this breakthrough that we don't think about it because we tend to not think about things that don't happen anymore.

That is a little bit of the problem with this, right? It's like the story of health progress is measured in non-events. It's the smallpox infection you didn't die of when you were five. It's the car accident that didn't kill you because you were wearing a seatbelt and there was an airbag. All these things that would have been. terrible, but you don't think about them because they didn't happen. This is an extraordinary achievement. Stephen made his argument on the TED stage in 2021.

But I want to stress not just that we did it, but I think the more interesting question is how we did it. That's what's been obsessing me over the last three or four years. That's the investigation I've been on trying to figure out what are the prime movers when we see change this momentous. What is really driving that change? A hundred years ago, there were less than two billion people on Earth. Today, there's almost 8 billion and counting. And we have that runaway population growth,

not because people started having more babies, but rather because people stopped dying. I mean, talk about optimism. That is the most fundamental form of good news there is. You are not dead, right? All this gets explored in Stephen's latest book, Extra Life, a short history of living longer. Talking to him about his research brings up so many questions about what our newfound

longevity might mean for us and the planet. And so today on the show, a conversation with Stephen Johnson about the past, present, end future of human life expectancy. We'll talk about why we started living longer and how much farther we can push it. Okay, so let's lay it. out just how bad things were and how unlikely you were to survive, especially if you were a child 100 years ago. Yeah, I mean, people would live to 70 or 80.

You know, that was not impossible to live that long. But a lot of people died at 55 or 50, and a lot of people died at two days or at two years or at the age of 10. Interesting, like when I first started thinking about this project, I had it in my head that it would probably come out in the year 2020 or 2021. And I thought that that would be a particularly relevant year because it would be the 100th anniversary of the end of the great influenza, the pandemic of 1918, 1919. And that was really the last point at which global life expectancy took a big downward turn. Upwards of 50 million people, we think, maybe even more, died in the great influenza when there were only 2 billion people on the planet, right?

And there's always been this question about the Spanish flu, which is that it didn't seem to leave a lot of scar tissue in the culture. There's not a lot of great poems or novels written about it. There's a million things written about World War I, but the influenza outbreak, which killed more people, didn't seem to leave a big aftermath. And honestly, I think the explanation of that mystery is that if you were an adult in 1920, you'd been born in the 19th century. And you were born into a world where basically a third of the population died before reaching adulthood. Respiratory viruses were a constant threat. Tuperculosis was a big killer. In some places, cholera was still a big killer.

smallpox was still around. And people dying from infections, antibiotics hadn't been invented. And so it was just a reality of life that people would just die all the time. And we weren't as attuned to the global situation because of the media limitations of the day. So when a influenza virus swept through your town and a bunch of your friends and relative died, it didn't feel all that different. And so that was what life was like. And also you had huge problems with famine at that point. You know, you would have these mass famines where millions of people would die. That was a big cause of death in the 20s 100 years ago. So it was a world where death was omnipresent. People could live to 70 or 80, but most people didn't. And also it was a world where childhood was the most dangerous

time of your life. And I think that that is something we just can't stress enough, both in terms of what it felt like to be a child, but also what it felt like to be a parent. You know, you just went into the world with this expectation that a third of your children would die. I mean, I can't imagine what that would be like. Well, you might be pleased to know that my siblings and I play a very dark game, which is called what would have killed us. So for my brother, it was his burst appendix. For me, I had strep throat so badly. Definitely would have killed me.

And none of us, according to our calculations, would have made it to age 20. But from what you're telling me, I think that that's a high estimate. We probably wouldn't have made it past the age of five. Well, first off, I just want to say don't really invite me over to holiday dinner. We're really fun, right? Yeah, we're super fun. It's a little dark over there. Well, we're appreciating life is what I'd like.

It's the better way to put it. No, I think that's right. It's a great exercise. You know, in my family, we've had some cancer scares that probably would have killed some of us at a young age. we've had, we have diabetes that probably would have killed some of us at a young age. And it's kind of like if you look at it like half the immediate family and my siblings, my parents, like half of our cohort would have died around 35 or before, have we been born 100 years before. So it's really important to take measure of that.

So as you mentioned, there are hundreds of reasons and innovations that compounded, doubled our life expectancy. Tell us how you decided which ones were the most important. You know, with this project, I'd had this original idea that I could go through the list of, you know, breakthrough innovations from the past and quantify exactly how many extra years of life you got or months of life maybe you got from each intervention. So, you know, on average, you got an extra six months of life because people invented seatbelts or, you know, and I thought that would be a great frame. It turns out to be impossible to do. There's just no, the data just is clear it off. It's hard to figure out. And all these interventions are kind of tied up with each other

in kind of complicated ways. So it's really hard to separate them out. So the closest thing you can really do, and a couple of folks have tried to do this in the past and I kind of built on their work, is basically rough orders of magnitude. So these are the interiors. interventions that saved, you know, millions of lives. These are the ones that saved hundreds of millions and then billions, you know, the big game changers. And so in the, in the billions category, and there is some argument about this, right? This is still kind of a rough estimate. But in the billions category, we have something like artificial fertilizer, which was crucial to the story of reducing famine, vaccines for obvious reasons. And then maybe the most kind of

surprising one, which is not, doesn't seem like a medical intervention, which is, which is, is toilets and sewers, basically separating the system that separates out our waste products, our human waste products, from our drinking water. And then below that, you have things like antibiotics, chlorination, also related to drinking water. That was a major kind of breakthrough. And then below that, you have a whole much longer list, and it could be longer than what I have in the book, but things like seatbelts and radiology and the AIDS cocktail and things

like that. But also, again, like toilets and sewers, they're innovations that don't necessarily seem medical initially, like refrigeration, for instance. Like being able to keep things cold was a major lifesaver. It was actually really useful for some of the other innovations like vaccines, right, because a lot of vaccines had to be kept cold. And so it was hard to get them when you didn't have electrical mechanical refrigeration. It was very hard to store vaccines and keep them safe. It was also hard to keep food fresh and keep it from getting contaminated. So refrigeration was a big, big game changer as well. After the break, more from my conversation with Stephen Johnson and the innovations that we take for granted that led to an incredible

explosion in human life expectancy. I'm Manus Zamarodi, and you're listening to the TED Radio Hour from NPR. We'll be right back. It's the TED Radio Hour from NPR. I'm Manus Zummerode. And on the show today, a conversation with author Stephen Johnson about why we're living longer, how we doubled human life expectancy over the last century. When you look at the story of human health and the progress we've made, scientists and medical professionals and public health officials are a huge part of that story, of course. But there is this other cast of characters that in some ways is equally important. And they are often made up of people who are not officially associated with medical professions or even scientists.

And they are people who are the kind of the activists or the evangelists or the explainers or the connectors who bring these new ideas and get them into circulation and persuade people to adopt these new medical interventions or whatever they are. One of Stephen's favorite examples of this is the somewhat surprising story of pasteurization. Yeah, I mean, pasteurization is the great case story in that because, you know, milk was a very dangerous thing in big cities, particularly in New York, where we both are. In the middle of the 19th century, it was very hard to get safe milk to drink. It was often contaminated because it wasn't refrigerated. They have these terrible swill milk kind of industrial farm factories in downtown Manhattan, where they would feed the cows, the waste products from whiskey distilleries, and you could get tuberculosis from milk. And it was particularly dangerous for young kids. You know, there's something like more than 50 percent of all deaths in New York in the 1850s were young children, and many of them were killed by contaminated milk in one form or another.

Why were we drinking it? I just have to ask. Like if it, you describe it as looking like a thin blue color. It sounds so disgusting. It's killing a lot of people. Why did we drink milk? Yeah. Well, it was partially that a lot of women were going into the kind of industrial factory workforce.

And so they were feeding young babies, cows milk instead of mother's milk. And that's why you had all these six-month-old year olds who were dying because they just didn't have another option. So there is a convention. story of how we solved this problem, which is we solved it with chemistry. We solved it with pasteurization. The pasture came up with this idea and the world changed. But in fact, there's this 50-year gap between pasteurization being developed originally in 1865 and 1915, which is roughly when pasteurized milk becomes standard in supermarkets and stores in the United States. And that's because it wasn't enough to just solve the problem with science and with chemistry. You had to fight for that solution to get into place, right? And that was a, that took, you know, social movements. I mean, it's one of the crazy things that I was only vaguely aware of before I started this project, which was that pasteurized milk was a big kind of political fight in the second half of the 19th century. And there were pasteurization activists and there were pasteurization rallies. And it sounds funny to us.

out because we take it for granted. But somebody had to fight for these ideas getting into circulation and getting into your refrigerator once refrigerators were invented. Milk, an important food for the health of the nation. Pasterized milk, a safe food, trusted by millions of people and important in every diet. For all these people, pasteurization is a guarantee of safety. There is no such thing as partly safe milk, for milk is either pasteurized or it isn't. And so there's a whole wonderful kind of range of, you know, 19th century muckrakers, this guy Frank Leslie,

who ran a newspaper in Brooklyn, who wrote all these exposés about the terrible milk trades. And then this guy, Nathan Strauss, who was a department store magnate. He owned Macy's, but he became a big pasteurization. advocate and kind of devoted his last couple of decades of his life to trying to get people to drink pasteurized milk. And eventually he, with a bunch of his allies, kind of turn the tide. And so there are a number of stories like that in the book. And what I ultimately started to realize

is that, you know, this is partially the triumph of enlightenment science on some level and reason and that kind of traditional story that you hear. But it's also the story. a story of kind of social struggle that the life expectancy doubling is related to other kind of marks of progress like universal suffrage or civil rights, right? It's something not just they came out of the laboratory, but actually came out of the streets and came out of struggle and argument and advocacy. And if you only focus on the scientists as important as they are, you miss a part of the story. And mortality rates dropped pretty quickly. Quickly, right, when pasteurization became standardized here in the U.S. in 1915, is that right?

This is a great example of why I couldn't precisely quantify the effect of, you know, each intervention the way I had originally envisioned in my initial idea for this project, because what happens is that pasteurization kicks in right at the exact same moment when people start chlorinating the drinking water in big cities. And so it's very hard to take. tell, you know, exactly which intervention is doing it. But what you see is this really, really dramatic drop in childhood and particularly infant mortality in the United States in that period. And it's interesting because sometimes people think that the progress in health is really just

a byproduct of progress economically, that people are just better off economically and they have more food on the table. And that's why they're living longer. And it's really driven by, you know, kind of capitalism on some level is making people wealthier. And that's why that's why we're healthier. But this is a great case study and why that is certainly not completely true and probably not true on some level, which is that

you see this incredible drop in childhood mortality right in the middle of the Great Depression. You know, like as all these coronation systems kick in and the pasteurization become standard and all that kind of stuff, you know, there's that whole cohort of kids that was born in the 30s actually lives a lot

longer than kids who were born, you know, at more affluent times 20 or 30 years before. And it's because the infrastructure of chlorination and pasteurization have been put in place by that point. Here's Stephen again on the TED stage. And there's another prime mover that we don't talk about enough, which seems a little bit unlikely in the context of, you know, disruptive innovation. And that is large bureaucratic institutions. Now, if that seems contradictory to you, I suggest that you flip through the pages

of any pharmaceutical drug catalog from the early 20th century. I mean, these things are just a laundry list of deadly poisons one after another, arsenic, mercury, belladonna, not to mention all the heroin and cocaine. A lot of medical historians believe that all-in, pharmaceutical drugs were a net negative

in terms of human health until the invention of antibiotics in the 1940s. That's what life was like. I mean, in 1937, there was this Tennessee pharma startup that hit upon this idea for a new cough syrup, a cure for strep throat actually, targeted at children. At the time, there was a new drug called sulfa drugs. They were kind of a forerunner of antibiotics,

but they were generally packaged in this bulky pill format. It was very difficult for kids to swallow. So a chemist at this startup came up with the brilliant idea of dissolving the sulfa drug in diethylene glycol, and then adding some raspberry flavoring to make it more palatable for the kids. seemed like a brilliant idea, except that diethylene glycol is toxic to human beings. It's basically antifreeze. And so almost immediately, weeks after,

there were dozens of deaths around the United States from this terrible concoction. And the crazy thing is that putting diethylene glycol in your medicine was not a problem, given the existing regulations of the day. The only thing that the FDA was really interested in was whether you were actually listing the ingredients of your medicine, potion on the label. So if you wanted to put antifreeze in your cough syrup, go right ahead, as long as you actually list the ingredients on the label. That's what life was like. But because of this tragedy, laws were changed, and for the first time, the FDA mandated the pharma companies show

that their drugs were not harmful to consumers, which seems kind of obvious, but somebody had to figure that out. And so what we needed at that point was not just kind of new miracle drugs. We needed new institutions. We need new meta-innovations, like three-phase trials and randomized controlled experiments and regulatory bodies like the FDA to separate out the fake cures from the real thing. And that kind of institutional innovation is going to be increasingly important in the decades to come. I mean, it is amazing. These scientific innovations compounded with government regulations plus public awareness campaigns. I mean, you could be talking about milk pasteurization or the FDA changing laws in the 30s.

Or you could be describing where we are right now when it comes to fighting COVID. Yes. I mean, here we are again, right? Yeah. And I mean, the first thing is that when you look at past crises and how we got out of them and when you look at the present crisis and think about how we might get out of it, one of the challenges in making sense of it all is precisely what you just said, which is there were all these different variables at play and all these different institutions and all these different disciplines and just not the number of people. And so trying to create a coherent vision of like what is really happening is very complicated. And it's complicated, you know, for me as as a storyteller, right? Like, how do you tell a story where there are a thousand heroes? It's really, it's very, you can't keep track of everybody, right? You know, it's like even harder than keeping track of like the number of, like, the number of. characters in Game of Thrones trying to figure out how to get track of all the characters

and the history of public health. So there's that complexity to it as well. But the other thing that is worth pointing out here, we sometimes place too much emphasis on the actual kind of physical objects of the breakthroughs like the vaccines. And in fact, when you really try and measure the changes that had the widest influence, but also the most kind of diffuse, it's sometimes these kind of meta innovations, which is the best example of this is something like randomized controlled trials, you know, which we think of in terms of the three-phase trials that we saw for the COVID vaccines, right? So, you know, creating a process whereby statistically you can create an assessment of whether a pill or a vaccine or some other medical intervention

works or doesn't work, that being able to do that because we invented this system of randomized control trials, double-blind trials, that is a superpower, right? I mean, before we had RCTs, as they're called, you know, there just really wasn't a way to tell whether a given drug worked or not. And it was all anecdote. And it was very misleading because people have a natural pharmacy in their bodies in the form of their immune system. And so no matter what pill you give them, they generally get better. And so there was a lot of like, hey, I gave this person some, you know, opium laced with mercury, and he got better. So that must work, you know. And so you just had all of this terrible, like, quack science well into the 20th century because we really didn't have a way of testing.

And it wasn't until surprisingly late, I think, actually, in the history of things, if you think about it. It wasn't until the late 1940s when RCTs were kind of formally developed as a procedure for testing whether a given intervention worked or not. And that was that was one of those, there's sometimes these innovations where they unlock a whole second generation of innovations in their wake. Like it suddenly became a lot easier to develop effective drugs once you had this new way of testing them. And, and we, again, it's a breakthrough really in statistics. So I understand why we don't, you know, have monuments celebrating its invention. But it really made a whole host of things possible, including the vaccine trials, right?

That was the whole, most of the year of 2020 was spent running RCTs on the first batch of COVID vaccines. And, you know, that was, because we were able to do that, we were able to determine that they were safe and that they worked. Can we talk more about our life expectancy now? Because, correct me if I'm wrong, but because of COVID, it's been the first time in a long time that our life expectancy has actually dropped. Is that right? In the United States, life expectancy was creeping backwards for the first time in a very long while before COVID because of the deaths of despair, as they're called. So the opioid epidemic and relatedly suicides that may have come out of kind of drug dependency. And one of the reasons why it started to creep down is that so many people dying from those things were very young, right?

So if you die at the age of 70, an average life expectancy in your country is 77, you don't really have a big effect on the overall average. but if a lot of people die at the age of 25 because they overdose on oxycontin or whatever drug, that will pull the overall average down. And so we had started to see this reversal, which was troubling already. And then COVID, you know, the data isn't fully out, but COVID in 2020, I think the latest numbers are that it declined by about a year in the United States, thanks to COVID. but crucially, it was about three times that for African-American communities, for instance. So there was not equally distributed. The loss of life was hit, was felt much harder in some communities inside the United States.

But, you know, it's clear that we have been going backwards. And the pandemic has accelerated something that was happening in the United States, not around the world, not in many places around the world that this was not the case, but it was true in the United States. So, you know, that was one of the other main reasons why I got engaged with this project, which was to say, this is not a victory lap. Like, we did not, you know, conquer death. And if we don't adhere to, if we don't learn from the lessons of the last 100 years and we don't keep applying ourselves to fixing the problems that we have, there's no reason to expect that this upward march of life expectancy is going to continue. It doesn't do it on its own. And so, you know, this, hopefully this has been a wake-up call that it can go backwards if we don't apply ourselves and continue to try and build on the, you know, successes of the past.

Yeah. I mean, on that note, it's pretty shocking how many of the problems that we've learned to fix over the past hundred years, how many of them still remain a problem throughout parts of the world? Something you wrote is that waterborne illnesses are still. still one of the most common causes of death. Yeah, and unlike, you know, some illnesses, like malaria or HIV, where we have some increasingly effective treatments or preventative measures, we know how to deal with contaminated water. You know, it's not a mystery. It just involves infrastructure. And the question is, you know, can, you know, that's just a matter of putting the infrastructure in place and paying for it.

for it. There are these kind of interesting new ideas about could you build, you know, kind of micro water waste removal and water purification systems that are not dependent on giant infrastructure being put in place. So if you have a small village that's kind of remote, you could create this little micro thing that would be solar powered and you could have the whole system without having to put in all the infrastructure that we would expect in kind of a modern city. And so that That may be one way in which we deal with the problem. But yeah, you kind of get back to there's some deep universals there, which is human beings need clean water.

And it's still, you know, after all the progress we've made, it's still something we haven't fully solved. Coming up more from Stephen Johnson on the unexpected consequences of people living longer. And where we go from here? I mean, currently the outer boundary of human life, somewhere around 110 and 115. It's very hard to live past that. But there is serious research out there that suggests that we can just blow past that boundary

and live for decades longer, maybe even indefinitely. I'm not saying this is going to happen, but it is on the table. I'm Anush Zameroody, and you're listening to the TED Radio Hour from NPR. Stay with us. Hey, if you're looking for a way to support our show and public media, I hope you will consider signing up for the NPR. Plus podcast bundle. You can listen to a bunch of NPR podcasts, including this one, without any sponsor breaks, and you can even access behind the scenes episodes from some of your favorite shows. Go find out more at plus.npr.npr.org. And thanks. It's the TED Radio Hour from NPR. I'm Anoush Zamorodi.

On the show today, why we're living longer. We're talking about the remote. remarkable innovations that have extended human life over the past hundred years. With us this hour is author Stephen Johnson, who says that with any kind of progress, inevitably, there are tradeoffs. No change this immense is entirely positive in its effects. I mean, I am glad that we doubled life expectancy. I think we should be generally glad that we doubled life expectancy, and I think we should try to keep going with it. But the truth is that what's happened is that basically people stopped dying. And the generations kind of stacked up.

And, you know, their children survived where they would have died before. And that has been driving the runaway population growth. And that runaway population growth has been driving the climate crisis. If you kept the population where it was in 1920, we wouldn't have climate change today. There just wouldn't be enough people. emitting enough carbon into the atmosphere. And so there's a strange, I think, truth here, which is that the climate crisis is the result of industrialization plus the triumph of public health and medicine. Which is, you know, it's a lot easier to be like demonizing the, you know,

the fossil fuel industry for ruining everything. But it actually is this weird secondary effect of this other thing as well that is generally kind of positive. And so all these things are, you know, bound up in complicated ways. The good news is that we think that, we think that, population growth is most likely going to level off in the second half of the 21st century and probably will peak around 10 billion, maybe 11 billion, but not go to 16 billion, not keep doubling. And then at that point, we actually would see a kind of a decreasing global population, presumably, which actually causes its own problems. It's not necessarily a great thing to have fewer people in your society generation after generation.

But let me get this straight. So if mortality rates had stayed what they were, a century ago, we wouldn't have climate change, which could be the big thing that actually humans' fatal mistake, as it were. Yeah, it's a weird feedback loop, right? Yeah. We didn't really fully think about that or ending famine. But it ended up being kind of the output of it. And climate as a problem came along with that.

Once you had that many people adopting an industrial lifestyle, it ended up having this this terrible effect on the overall atmosphere. Do you want to talk about in the more immediate present? What is our life expectancy right now? It depends on where you are. In the United States, we actually don't know what the exact number would be now because there's so much changing with COVID, but I would imagine it's somewhere around 76 or 77. And globally, it's somewhere right around 70.

Again, it's hard to tell because there's been so many COVID deaths. And, you know, a couple of interesting facts in there. there, the fastest growing age cohort in countries like the United States are people who live into their hundreds. What? They are? Seriously? Yeah.

I mean, now, it's a small group, but it's growing. And, you know, my grandmother died at almost at the age of 105. Like, she made it to 104. Oh. Almost made it to 105. And my other grandmother lived to 99. And, you know, that was just really, really unusual 100 years ago or 200 years ago. But so I would immediately think, like, oh, that.

Stephen Johnson, you have very good genes. But is it more than that now? Yeah, I have the good genes. I'm just, you know, really wasting them with my debauched lifestyle that I know. So I don't know. Actually, you know, my grandmother enjoyed a martini well into her hundreds every night, more or less. So I don't know what that says about anything. But, you know, I mean, I think one of the things that is beautiful about this is the intergenerational contact that longevity brings to society. Like my grandmother, you know, lived to 104, really got to develop a rich relationship with her great-grandchildren, you know, some of whom were 16 when she died.

And that is just a healthy thing for society. I mean, we think about the kind of values of diversity in society, right? And to me, one of the ones that we don't talk about enough is generational diversity, getting to know people and really being close to people, whether they're friends or family, who are 50 years older than you or 50 years younger than you. There's so much perspective and, again, kind of long-term thinking you get by interacting with people who were born almost a century ago.

And so we'll have more of that going forward almost certainly. And I think that that's part of this that I think is just uniformly positive in its effects. I mean, there are, though, people right now who, are saying like, yeah, and actually we're going to live well into our 150s. We might even stop aging or eliminate death. What are your thoughts about ending the aging process, increasing longevity? Is that just like some Silicon Valley dream or are you feeling like, yeah, there's something to it? I guess I would say two things.

there's this idea lifespan. How long do you live? But there's a related but different category, which is health span, which is how long are you alive where you're fundamentally healthy and in control of all your faculties, you know, maybe with some limitations

as you get older, but you're in control of your destiny on some level physically and mentally. And those are two different things. Like we've gotten really good at keeping people alive, but oftentimes the last 10 years of their lives are not great. And so there's a lot of interest right now, and I think this is wonderful,

in trying to extend health span and really trying to extend that period of your life, you know, in your kind of in your 20s and your 30s. It's very interesting kind of biological period in your life, which is you've stopped growing, you've stopped developing, but you haven't yet started aging. And it's, yeah, we're just like, oh, I remember those days. I remember those days. And, you know, we now kind of understand a little bit of what's happening. And I'm not an expert in this, but basically, you know, there is kind of constant maintenance of all your cells. Your cells are constantly dying and being replaced by new cells, but, you know, they're being replaced effectively. And the new cells that come in are not kind of pre-aged in some way.

And for complicated reasons, we're just starting to tease out. There's a clock that starts ticking on a cellular level somewhere in your late 30s, early 40s, where that, that, automated repair process. It's not just that it kind of declines and function just over age. There seems to be some kind of genetic programming that turns it off on some level. And the idea is if we could figure out what that programming is, maybe we could actually instruct ourselves not to flip that switch and actually keep repairing the body. and thus extend health span.

So when you're 60 or 70, you really fundamentally feel like you might be 30. And on a biological level, you might be more like a 30-year-old than a 60-year-old today. And that all seems good to me. I mean, you know, whatever it is, just tell me what to take. You know, what we don't know is whether that pushes the outer boundary of the human life. Like right now, almost nobody lives past 110. But 30 years ago, it was very hard to live past 100. Right.

And so we have consistently been pushing that outer boundary over time. And so the question is, like, can that continue? And maybe can that even accelerate so that we start talking about people regularly living relatively satisfying lives to 120 and then 130. But overall, the science here is interesting and real. and it's coming in some fashion. Can I ask you, so in addition to watching, of course, policy and how countries are going to deal with cutting emissions so that we don't fry our planet,

what are some of the advances and innovations that you're watching most closely that may lead to an increased life expectancy? I would say the two most interesting ones in the sense that we are seeing results from them right now are immunotherapies, which in some ways are, you know, a sequel to vaccines, right? A vaccine in a sense, like, it's an outside intervention that kind of supercharges your own innate immune system to do the work for you. It just figures out

how to get your immune system kind of trained in a certain way. But ultimately, like, it's you, it's your immune system that's doing the work of fighting off the smallpox infection after you've been vaccinated against smallpox, for example. So immunotherapies are taking that similar approach with treating things like cancer, right? Your body is constantly fighting cancer cells all the time successfully. And just every now and then a rogue mutating cell escapes the immune system and kind of tricks the immune system basically into ignoring it. And we've, we've learned that signal. We've figured out what that signal is. And so now we're kind of figuring out, can we build, you know, medical interventions that basically keep the cancer cells from lying

about their identity. So that is happening. And then the other thing I would say is machine learning and artificial intelligence. We're already using machine learning and AI as a drug discovery mechanism. So instead of just, you know, the classic penicillin story where it's like Alexander Fleming is like, oh, I found this weird mold

in my petri dish that I left out. I wonder if that'll help us fight bacteria. You know, just total serendipity. Like, just try things and see what works. That's how we invented, you know, drugs for a really long time. And then we got a little better at it. But the idea here is that these new machine learning

algorithms can basically just run through trillions of potential combinations of proteins or molecules or whatever and come up with these potential new drugs. And it's kind of like the job of the computer is to say, here's 10 interesting candidates that I've culled together from exploring this vast possibility space of different molecular combinations. Take these and go test them. So I think immunotherapies and machine learning right now we're starting to see results. And there's going to be a lot of that in the next decade. There is serious research out there that suggests that we can just live for decades longer, maybe even indefinitely. I'm not saying this is going to happen, but it is on the table. And the thing about it is, if we did do that, it would be the most momentous change

in the history of our species, right? Initially, it would intensely increase the health and inequalities in the world, because only rich people could afford these treatments originally. It would greatly exacerbate our runaway population growth problem, and it would fundamentally alter the definition of the arc of a human life. When you ask people, do you think we should mess around with immortality? Ordinary people? Most of them say no. But the problem is we don't have, collectively, a decision-making body that can help us wrestle with changes this immense.

We're like the FDA back in 1930, like, go ahead and make your immortality pill, just make sure the ingredients are right on the label. That's where we are. So the kinds of innovations we need are going to be on the level of oversight and decision-making. And I think we can make these innovations if we work at it. But to my mind, we should be focusing less on extending life indefinitely and more on reducing the gaps that remain in health outcomes here. here and around the world.

I mean, just look at what we've lived through in the past year and a half. On average, white Americans lost one year of expected life in 2020, thanks largely to COVID. African Americans lost three years. And we should be focusing on reducing the gap between what we call health span and lifespan, the amount of time that we spend

that is fundamentally healthy and at full capacity. I think we all agree that these are problems that are worth solving, and we have the tools at our disposal right now to solve them. If the first great revolution in human health was extending the overall average human life, the second should be about closing the gaps. I guess to wrap up, Stephen, I'm wondering,

can you be wax a little philosophical for me? Because you must live your life differently, knowing all the various ways our lives have been extended. And on the one hand, it makes you slow down and think, you know, very thoughtfully, like, this is clean water coming out of my tap. The takeout that I order has to be cooked and packaged according to certain standards. Yeah. But the climate change aspect of it, I wondered if that sort of makes you stop in your tracks and think, like, this is a story of the last century, but it's definitely not the story of the next century. You know, it's a great question.

day to day, it's hard to keep that sense of wonder and amazement. Like, you can't just be the guy who every time someone asked for a glass of water, you're like, but do you realize how incredible water is? Yeah, that would be rather tedious. But what I remember, actually, the thing that came to mind when you just said that is going to get the first vaccine dose in February, I think. I got it pretty early. And I went out to the racetrack in Queens here where they had a vaccine. vaccination center. And I actually kind of teared up when I got the shot, not because it was painful.

It actually isn't painful. I should say to anybody who's worried about the pain of it. But I just, I think because of this project, like, I just thought of all the people and creativity and hard work that like went into inventing vaccines and inventing this particular vaccine. And there was just, you know, hundreds of years of kind of brilliant, tenacious mind. trying to solve this problem to keep me safe. And it just seemed like this wonderful kind of crystallization of all this history. And it was very, it was weirdly moving. And so when you think about that positive trajectory of all those lives that were saved,

that were the beneficiaries of all that kind of intellectual work and political work that made that possible, I think that's a really important feeling to have in your body on some level, just to remind yourself of like what has come before. you. But you have to then temper it with a sense of problems still exist and there are looming problems. And we can project forward now and say where we are in terms of climate or in terms of other things, we may be in trouble, in serious trouble 10 years from now, or 20 years from now, or 30 years from now. And that requires that long-term thinking in a way that we began with, right, with the 100-year newspaper. Right, right. How do you get your brain to think long-term?

about not just the legacy of your actions right now for you and your immediate family, but the legacy of your actions for your children's children and your great-grandchildren. And that's a hard thing for the human brain to do. It doesn't come naturally to us. And that is not something that people used to do. People did not sit around and say, hey, here we are in our society right now. But let's look at current trans and project forward 50 years and think about, you know, how we could anticipate those future problems and what we could do.

now to make sure that those future problems don't happen in 50 years or in 30 years. That's just not a way of thinking that humans have historically done. And now we're trying to do it. And we're not great at it yet, for sure. But the fact that we're even trying and we're learning those new skills that we are trying to develop that long-term thinking, that is what makes me cautiously optimistic about our ability to, to solve these new problems. That's author Stephen Johnson.

His latest book is called Extra Life, a short history of living longer. You can see the Extra Life TV series on PBS. And watch all of Stephen's TED Talks at TED.com. Thank you so much for listening to our show this week about why we're living longer. This episode was produced by Rachel Faulkner and Diba Motisham. It was edited by James Delahousie and Katie Samp.

Simon. Our TED Radio production staff also includes Fiona Gehrin, Katie Montalione, Sylvie Douglas, Matthew Cloutier, and Margaret Serino. Our audio engineer is Brian Jarbo. Our theme music was written by Romteen Arablewe. Our partners at TED are

Chris Anderson, Colin Helms, Anna Feelin, Michelle Quint, Sammy Case, and Danielle Bellarzzo. I'm Manusse Zamorodi, and you've been listening to the TED Radio Hour from NPR.